"""
Backend to the console plugin.

@author: Eitan Isaacson
@organization: IBM Corporation
@copyright: Copyright (c) 2007 IBM Corporation
@license: BSD

All rights reserved. This program and the accompanying materials are made 
available under the terms of the BSD which accompanies this distribution, and 
is available at U{http://www.opensource.org/licenses/bsd-license.php}
"""
# this file is a modified version of source code from the Accerciser project
# http://live.gnome.org/accerciser

import gtk
import re
import sys
import os
import pango
from StringIO import StringIO

try:
    import IPython
except Exception,e:
    raise "Error importing IPython (%s)" % str(e)


ansi_colors = {
        '0;30': 'Black',
        '0;31': 'Red',
        '0;32': 'Green',
        '0;33': 'Brown',
        '0;34': 'Blue',
        '0;35': 'Purple',
        '0;36': 'Cyan',
        '0;37': 'LightGray',
        '1;30': 'DarkGray',
        '1;31': 'DarkRed',
        '1;32': 'SeaGreen',
        '1;33': 'Yellow',
        '1;34': 'LightBlue',
        '1;35': 'MediumPurple',
        '1;36': 'LightCyan',
        '1;37': 'White'}

class IterableIPShell:
    def __init__(self,argv=None,user_ns=None,user_global_ns=None,
                             cin=None, cout=None,cerr=None, input_func=None):
        if input_func:
            IPython.iplib.raw_input_original = input_func
        if cin:
            IPython.Shell.Term.cin = cin
        if cout:
            IPython.Shell.Term.cout = cout
        if cerr:
            IPython.Shell.Term.cerr = cerr

        if argv is None:
            argv=[]

        # This is to get rid of the blockage that occurs during 
        # IPython.Shell.InteractiveShell.user_setup()
        IPython.iplib.raw_input = lambda x: None

        self.term = IPython.genutils.IOTerm(cin=cin, cout=cout, cerr=cerr)
        os.environ['TERM'] = 'dumb'
        excepthook = sys.excepthook
        self.IP = IPython.Shell.make_IPython(argv, user_ns=user_ns,
            user_global_ns=user_global_ns,
            embedded=True,
            shell_class=IPython.Shell.InteractiveShell)
        
        self.IP.system = lambda cmd: self.shell(self.IP.var_expand(cmd), 
                header='IPython system call: ',
                verbose=self.IP.rc.system_verbose)

        sys.excepthook = excepthook
        self.iter_more = 0
        self.history_level = 0
        self.complete_sep = re.compile('[\s\{\}\[\]\(\)]')

    def execute(self):
        self.history_level = 0
        orig_stdout = sys.stdout
        sys.stdout = IPython.Shell.Term.cout
        try:
            line = self.IP.raw_input(None, self.iter_more)
            if self.IP.autoindent:
                self.IP.readline_startup_hook(None)
        except KeyboardInterrupt:
            self.IP.write('\nKeyboardInterrupt\n')
            self.IP.resetbuffer()
            # keep cache in sync with the prompt counter:
            self.IP.outputcache.prompt_count -= 1

            if self.IP.autoindent:
                self.IP.indent_current_nsp = 0
            self.iter_more = 0
        except:
            self.IP.showtraceback()
        else:
            self.iter_more = self.IP.push(line)
            if (self.IP.SyntaxTB.last_syntax_error and
                    self.IP.rc.autoedit_syntax):
                self.IP.edit_syntax_error()
        if self.iter_more:
            self.prompt = str(self.IP.outputcache.prompt2).strip()
            if self.IP.autoindent:
                self.IP.readline_startup_hook(self.IP.pre_readline)
        else:
            self.prompt = str(self.IP.outputcache.prompt1).strip()
        sys.stdout = orig_stdout

    def historyBack(self):
        self.history_level -= 1
        return self._getHistory()

    def historyForward(self):
        self.history_level += 1
        return self._getHistory()

    def _getHistory(self):
        try:
            rv = self.IP.user_ns['In'][self.history_level].strip('\n')
        except IndexError:
            self.history_level = 0
            rv = ''
        return rv

    def updateNamespace(self, ns_dict):
        self.IP.user_ns.update(ns_dict)

    def complete(self, line):
        split_line = self.complete_sep.split(line)
        possibilities = self.IP.complete(split_line[-1])
        if possibilities:
            common_prefix = reduce(self._commonPrefix, possibilities)
            completed = line[:-len(split_line[-1])]+common_prefix
        else:
            completed = line
        return completed, possibilities

    def _commonPrefix(self, str1, str2):
        for i in range(len(str1)):
            if not str2.startswith(str1[:i+1]):
                return str1[:i]
        return str1

    def shell(self, cmd,verbose=0,debug=0,header=''):
        stat = 0
        if verbose or debug: print header+cmd
        # flush stdout so we don't mangle python's buffering
        if not debug:
            input, output = os.popen4(cmd)
            print output.read()
            output.close()
            input.close()

class ConsoleView(gtk.TextView):
    def __init__(self):
        gtk.TextView.__init__(self)
        self.modify_font(pango.FontDescription('Mono'))
        self.set_cursor_visible(True)
        self.text_buffer = self.get_buffer()
        self.mark = self.text_buffer.create_mark('scroll_mark',
                                                                                         self.text_buffer.get_end_iter(),
                                                                                         False)
        for code in ansi_colors:
            self.text_buffer.create_tag(code,
                                                                    foreground=ansi_colors[code],
                                                                    weight=700)
        self.text_buffer.create_tag('0')
        self.text_buffer.create_tag('notouch', editable=False)
        self.color_pat = re.compile('\x01?\x1b\[(.*?)m\x02?')
        self.line_start = \
                                self.text_buffer.create_mark('line_start',
                                                self.text_buffer.get_end_iter(), True
                                )
        self.connect('key-press-event', self._onKeypress)
        self.last_cursor_pos = 0

    def write(self, text, editable=False):
        segments = self.color_pat.split(text)
        segment = segments.pop(0)
        start_mark = self.text_buffer.create_mark(None,
                                                                                            self.text_buffer.get_end_iter(),
                                                                                            True)
        self.text_buffer.insert(self.text_buffer.get_end_iter(), segment)

        if segments:
            ansi_tags = self.color_pat.findall(text)
            for tag in ansi_tags:
                i = segments.index(tag)
                self.text_buffer.insert_with_tags_by_name(self.text_buffer.get_end_iter(),
                                                                                         segments[i+1], tag)
                segments.pop(i)
        if not editable:
            self.text_buffer.apply_tag_by_name('notouch',
                                                                                 self.text_buffer.get_iter_at_mark(start_mark),
                                                                                 self.text_buffer.get_end_iter())
        self.text_buffer.delete_mark(start_mark)
        self.scroll_mark_onscreen(self.mark)

    def showPrompt(self, prompt):
        self.write(prompt)
        self.text_buffer.move_mark(self.line_start,self.text_buffer.get_end_iter())

    def changeLine(self, text):
        iter = self.text_buffer.get_iter_at_mark(self.line_start)
        iter.forward_to_line_end()
        self.text_buffer.delete(self.text_buffer.get_iter_at_mark(self.line_start), iter)
        self.write(text, True)

    def getCurrentLine(self):
        rv = self.text_buffer.get_slice(self.text_buffer.get_iter_at_mark(self.line_start),
                                                                        self.text_buffer.get_end_iter(), False)
        return rv

    def showReturned(self, text):
        iter = self.text_buffer.get_iter_at_mark(self.line_start)
        iter.forward_to_line_end()
        self.text_buffer.apply_tag_by_name('notouch',
                                                                             self.text_buffer.get_iter_at_mark(self.line_start),
                                                                             iter)
        self.write('\n'+text)
        if text:
            self.write('\n')
        self.showPrompt(self.prompt)
        self.text_buffer.move_mark(self.line_start,self.text_buffer.get_end_iter())
        self.text_buffer.place_cursor(self.text_buffer.get_end_iter())

    def _onKeypress(self, obj, event):
        if not event.string:
            return
        insert_mark = self.text_buffer.get_insert()
        insert_iter = self.text_buffer.get_iter_at_mark(insert_mark)
        selection_mark = self.text_buffer.get_selection_bound()
        selection_iter = self.text_buffer.get_iter_at_mark(selection_mark)
        start_iter = self.text_buffer.get_iter_at_mark(self.line_start)
        if start_iter.compare(insert_iter) <= 0 and \
                    start_iter.compare(selection_iter) <= 0:
            return
        elif start_iter.compare(insert_iter) > 0 and \
                    start_iter.compare(selection_iter) > 0:
            self.text_buffer.place_cursor(start_iter)
        elif insert_iter.compare(selection_iter) < 0:
            self.text_buffer.move_mark(insert_mark, start_iter)
        elif insert_iter.compare(selection_iter) > 0:
            self.text_buffer.move_mark(selection_mark, start_iter)


class IPythonView(ConsoleView, IterableIPShell):

    def __init__(self, main):
        ConsoleView.__init__(self)
        self.cout = StringIO()
        IterableIPShell.__init__(self, cout=self.cout, 
                cerr=self.cout, input_func=self.raw_input,
                user_ns={'main':main})
        self.connect('key_press_event', self.keyPress)
        self.execute()
        self.cout.truncate(0)
        self.showPrompt(self.prompt)
        self.interrupt = False
        self.changeLine("main.canvas.inspect()")
        self._processLine()

    def raw_input(self, prompt=''):
        if self.interrupt:
            self.interrupt = False
            raise KeyboardInterrupt
        return self.getCurrentLine()

    def keyPress(self, widget, event):
        if event.state & gtk.gdk.CONTROL_MASK and event.keyval == 99:
            self.interrupt = True
            self._processLine()
            return True
        elif event.keyval == gtk.keysyms.Return:
            self._processLine()
            return True
        elif event.keyval == gtk.keysyms.Up:
            self.changeLine(self.historyBack())
            return True
        elif event.keyval == gtk.keysyms.Down:
            self.changeLine(self.historyForward())
            return True
        elif event.keyval == gtk.keysyms.Tab:
            if not self.getCurrentLine().strip():
                return False
            completed, possibilities = self.complete(self.getCurrentLine())
            if len(possibilities) > 1:
                slice = self.getCurrentLine()
                self.write('\n')
                for symbol in possibilities:
                    self.write(symbol+'\n')
                self.showPrompt(self.prompt)
            self.changeLine(completed or slice)
            return True

    def _processLine(self):
        self.history_pos = 0
        self.execute()
        rv = self.cout.getvalue()
        if rv: rv = rv.strip('\n')
        self.showReturned(rv)
        self.cout.truncate(0)
